var event=require('events')
var eventEmitter=new event.EventEmitter();

eventEmitter.on('hasaki',function(a,b){
  console.log('hasaki',a,b);
})
eventEmitter.on('hasaki',function(a,b){
  console.log('biubiu',a,b);
})

eventEmitter.emit('hasaki','balala','muji');

var eventListener=eventEmitter.listenerCount('hasaki');
console.log('kasaki:'+eventListener);            // kasaki:2